Raised beds look simple—fill, plant, harvest—but success hinges on what’s under your seedlings’ roots. After a full growing season trialling three soil approaches in Wollongong, Perth and Cairns, we’ve locked in the mix that keeps veggies pumping and microbes humming. Below you’ll find the data, the exact recipe, climate tweaks, and where GreenSpace Raised Garden & Container Potting Soil slots in to save you time and backache.
Why Your Soil Choice Makes or Breaks a Raised Bed
-
Root Real Estate: Limited depth means every litre must balance drainage, air and nutrition.
-
Water Management: Australian heat swings from torrential to crispy-dry; the right blend buffers both.
-
Long-Term Fertility: Beds are a living ecosystem—organic matter and minerals need topping up, not replacement.
Inside the Perfect Raised-Bed Mix
|
Component |
Job in the Bed |
|
Bank moisture without waterlogging |
|
|
Compost & Composted Manure |
Slow-release nutrition and biology burst |
|
Natural chitin for pest resistance and steady N boost |
|
|
Perlite & Scoria |
Keep channels open for air and fast drainage |
|
Trace elements for flavour-packed produce |
Shortcut: All of the above land in one bag of our GreenSpace Raised Garden & Container Potting Soil.
The Dr Greenthumbs Raised-Bed Soil Method
-
Measure up. Calculate volume with our free Soil Volume Calculator to avoid last-minute Bunnings dashes.
-
Layer smart (optional). Beds deeper than 400 mm can use rough woody offcuts or straw in the bottom 100 mm, then top with premium soil to save dollars.
-
Fill with GreenSpace. Its pre-blended fertiliser feeds for the first month—perfect while seedlings establish.
-
Top-dress at week 5. Add a handful of slow-release organic pellets or compost per plant.
-
Mulch & water deeply. Finish with 50 mm of straw or chip mulch; water until runoff, then pause until top 30 mm is dry.
Climate Tweaks
Temperate & Coastal (Sydney, Melbourne)
-
Mix remains as-is—just mulch thickly before summer.
Sub-Tropical (Brisbane, Darwin)
-
Blend 10 % extra scoria or perlite to boost airflow in sticky humidity.
Arid & Hot Inland (SA, WA interiors)
-
Fork in 5 % biochar or extra coco coir for extra moisture holding.
How Much Soil Do I Need?
Multiply length × width × depth (m) to get cubic metres, then multiply by 1 000 to convert to litres. Our 27 L GreenSpace bag covers roughly 0.027 m³—but the calculator figures it out in seconds.
Sustainable & Organic by Design
GreenSpace is built from plant-based and mineral inputs only—no biosolids, sludge or mystery fillers—so it’s safe for kid-snacked cherry tomatoes and late-night herb raids. Each bag is blended in NSW, keeping the carbon footprint lean while supporting local jobs.
Frequently Asked Questions
Does GreenSpace work in self-watering wicking beds?
Absolutely. The coir-peat combo wicks like a champ while light minerals stop soggy roots.
How often should I replace the soil?
You don’t—refresh with compost and nutrients each season, and the mineral fraction keeps on giving.
Bag sizes?
27 L and 45 L. Most 1 × 1 m beds (30 cm deep) take 11 of the 27 L bags.
Ready to Grow?
Skip the soil maths and guesswork—grab GreenSpace Raised Garden & Container Potting Soil today, fill your beds this weekend and watch those seedlings bolt. Free shipping options kick in at $250, so bundle a few bags and kiss delivery fees goodbye.
Happy growing, legend! 🌱
About the Author
